cache-test: fix some minor things pointed out by coverity
cache-test: fix some minor things pointed out by coverity

fanc999/libsoup,fanc999/libsoup,jwendell/libsoup,jwendell/libsoup,Distrotech/libsoup,fanc999/libsoup,Distrotech/libsoup,Distrotech/libsoup,fanc999/libsoup,jwendell/libsoup,jwendell/libsoup,jwendell/libsoup,Distrotech/libsoup,Distrotech/libsoup,fanc999/libsoup